Pesticides, such as insecticides, are commonly used in agricultural, industrial, and residential settings to battle destructive, pestiferous, or disease-carrying insects and other animals. Pesticides have achieved significant successes in controlling pestiferous and disease-vector animals, and have increased in their lethality over the years. However, increasingly the environmental and human health effects of pesticides, as well as their deleterious effects on beneficial insect species and other animals, have caused users to seek other means for controlling pest populations.
For example, many stink bugs and shield bugs (order Hemiptera; family Pentatomidae) are considered agricultural pest insects, although some are beneficial insects. Examples include the spined soldier bug, Podisus maculiventris, several species of Euschistus spp., the red-shouldered stink bug, Thyanta pallidovirens, the green stink bug, Acrosternum hilare, the conchuela stink bug, Chlorochroa ligata, Uhler's stink bug, C. uhleri, and Say's stink bug, C. sayi, Some can generate large populations that damage crop production and are resistant to many pesticides. Moreover, they are immune to genetically modified crops, such as Bt crops. Over the past 5-10 years, stink bugs and plant bugs have become a serious agricultural pest problem in many parts of the world, especially in the regions with large areas of Bt crops.
As an example, the brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) native to Asia, is believed to have been accidentally introduced into the United States as early as 1996, likely as a collection of stowaways, possibly as eggs, on packing crates or the like. The BMSB has been recorded in a total of 33 states and the District of Columbia, according to information provided by the U.S. Department of Agriculture and the National Pest Management Association. In 2010, the BMSB emerged as a severe pest of fruit and other crops across the region. In addition, this invasive species is a serious nuisance for homeowners and businesses as it overwinters in residential houses, commercial buildings, and warehouses.
Aggregation pheromone components have been identified from many species of agriculturally important stink bugs. In 2008, Zahn et al. noted that for all phytophagous pentatomids for which sex or aggregation pheromones have been identified, the compounds were produced by males. J. Chem. Ecol. 34:238 (2008). Males of Thyanta spp., for example, produce methyl (2E,4Z,6Z)-decatrienoate with (Millar, Tetrahedron Lett. 38:7971 (1997); McBrien et al., J. Chem. Ecol. 28:1797 (2002)) or without particular sesquiterpenes (Moraes et al., J. Chem. Ecol. 31:1415 (2005)) that attract a mate. J. G. Millar et al. reported findings regarding male-produced pheromone components of several agriculturally important stink bugs, including T. pallidovirens, A. hilare, C. sayi, C. uhleri, and C. ligata. Bull. Int. Org. of Biol. Control, Pheromone Working Group 25:1 (2002). Methyl 2E,4Z-decadienoate has been identified as an aggregation pheromone component or field attractant for seven Euschistus spp. (Aldrich et al., Environ. Entomol. 20:477 (1991)), and has been used for stink bug monitoring programs in agricultural settings. Another methyl ester, methyl 2E,4E,6Z-decatrienoate, was identified as an aggregation pheromone component of the stink bug Plautia stali Scott (Sugie et al., Appl. Entomol. 31:427 (1996)) and as a field attractant for both adults (males and females) and nymphs of the BMSB, Halyomorpha halys (Stål) and A. hilare (Aldrich et al., J. Chem. Ecol. 33:801 (2007)); Khrimian, Tetrahedron 61:3651 (2005)). Recently, a sesquiterpene epoxyalcohol, murgantiol, was identified by Zahn et al., J. Chem. Ecol. 34:238 (2008), as an aggregation pheromone component of the Harlequin bug, Murgantia histrionica (Hahn).
Among the economically important phytophagous pentatomid stink bugs, some of them, such as the BMSB and the boxelder bug, Boisea trivittata (Say), are also serious nuisances for homeowners and businesses as they overwinter in residential houses, commercial buildings, and warehouses.
Attractant-baited stink bug traps are effective for trapping various stink bugs outdoors. However, when the stink bugs begin to overwinter and go indoors when the weather cools in late fall, they may no longer be attracted by any known pheromone attractant (active during the summer) in the traps. Unfortunately, there are no known semiochemical attractants that are active for these nuisance stink bugs indoors during their overwintering period. Methods and compounds for attracting stink bugs, such as attracting them to traps, are still needed to control these pests.